Question

Which of these is correct for the central difference scheme?

(a) Neither numerical dispersion nor numerical diffusion error arises

(b) Only numerical diffusion error arises

(c) Both numerical dispersion and numerical diffusion errors arise

(d) Only numerical dispersion error arises

This question was addressed to me in examination.

The question is from Convection-Diffusion Problems topic in division Convection-Diffusion Problems of Computational Fluid Dynamics

Answer 1

Right answer is (d) Only numerical dispersion error arises

The explanation: For the central differencing scheme, there is no problem of numerical diffusion. Only numerical dispersion error arises here. This is because, the k-value is completely imaginary and free from a real part.